Unit2HealthylifestyleDiscoveringUsefulStructuresP17课件高中英语人教版选择性

新人教选择性必修Book3Unit2HealthyLifestyleDiscoverusefulstructuresP17infinitiveassubject不定式作主语toenablethestudentstomastertheusageoftheinfinitiveoftheverbasthesubjecttoenablethestudentstousetherelevantgrammarflexiblyandauthenticallyintherealsituationLearningObjectivesUnderlinethesentencesinthetextandanalsysethefunction.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.主语Topreventharmfulhabitslikethesefromdominatingateenager’slifeisessential.主语Theymustlearntorecognisebadhabitsearlyandmakeappropriatechanges.宾语Tochangebadhabitsisnevereasy,evenwithmanyattempts.主语Wemakeachoicetodosomething,andthenwerepeatitoverandoveragain.定语Lead-inFindmoreintherestofthetext.Presentation/PracticeMymumkeepstellingmetogooutwithmyschoolfriendsinstead.It’simportanttomeetfriendsinpersonfromtimetotime,notjustonsocialmedia.WhenIsetouttodosomething,Idomybesttoachieveit.Mytargetistopreparemyselfformydegreeinbiologyatuniversity.LiYingisthefirstpersontojointhevolunteeringclubinherclass.complement宾语补足语subject主语adverbial状语predicative表语attribute定语Listthefunctionsoftheinfinitivesinthesentences.动词不定式

动词不定式作主语

不定式作主语，表示具体的、一次性的或将来的动作；在很多情况下，人们通常用it作为形式上的主语，而把不定式移到谓语之后，使句子结构显得平稳一些。Toseeistobelieve.眼见为实（Seeingisbelieving)Itisessentialtogiveupsmoking.It’sveryniceofyoutohelpme.1.不定式具有名词的特征，可在句子中充当主语。

Toknowoneselfisdifficult.

人贵有自知之明。

动词不定式作主语

不定式和动名词作主语的区别不定式：表示具体的某次动作，一次性的，将来的动作。

Toteachyoutheusesoftheinfinitiveismytasktoday.

教你们不定式的用法是我今天的任务。动词-ing形式：表示比较抽象的、经常性的、一般性动作。

Teachingismyjob.

教学是我的工作。2.不定式和when/where/how/what/whether等连用，在句子中

作主语。Whethertodoit

hasn’tbeendecided.是否去做还没有决定。Itis+形容词+forsb.+todosth.常用于表示事物的特征特点，表示客观形式的形容词，如easy,hard,difficult,interesting,impossible等。Itis+形容词+ofsb.+todosth.的句型一般用表示人物的性格、品质，表示主观感情或态度的形容词，如good,kind,nice,clever,foolish,right等。3.it作形式主语句型：It’sverysillyofyoutofoolme.It’sverysillyforyoutodosuchthing.4.Itis+a/an+名词+todosth.这样的名词有：apity,ashame,apleasure,one’sduty,anhonor等。It’sagreathonortobeinvitedtoyourbirthdayparty.很荣幸被邀请参加你的生日聚会。

动词不定式作主语

5.Ittakes/costs/requires/makessb./sth.todosth.Ittookmetwohourstofinishthework.我完成那项工作用了两小时。注意：在Itis+nouse/nogood/useless/fun/enjoyable/tiring/interesting/foolish/nice/awasteoftime/apleasure...句型中常用动名词形式做真正的主语。It’snousewaitingheredoingnothing.It’snouseforustowaitheredoingnothing.

（1）Sometimesit’sbetter

___(remain)silent.（2）Although

isahardtasktoprotectourenvironment,wecan’thelpbutgoahead.

（3）

______

(control)theairpollutionisnecessary.（4）Itwasfoolish

himtoendangerhislifeinthatway.（5）Don’tyouthinkitisrude

himtoaskaladyherage?Practice语法填空：根据提示完成句子。ofofitTocontrol/Controllingtoremain（6）Itisdifficult

himtoliveonsuchasmallsalary.（7）Idon’tthink_________________________（你问……是不

礼貌的）howlongtheinterviewwilllast.（8）

_____

（保卫……是我们的职责）thecountryagainstitsenemies.（9）

___

（……花了我半个小时）towashtheclothes.Practice语法填空：根据提示完成句子。foritisimpoliteofyoutoaskIt’sourdutytodefendIttookmehalfanhour ProductionJointhewordstomakefullsentencesusingtheinfinitive.1.important/avoid/passivecigarettesmoking._________________________________________________2.willtake/nutritionspecialist/abalanceddietmenu/make/anhour/foryou.____________________________________________________________________________________________________2Itisimportanttoavoidpassivecigarettesmoking.Itwilltakeanhourforanutritionspecialisttomakeabalanceddietmenuforyou.ProductionJointhewordstomakefullsentencesusingtheinfinitive.3.useful/turnto/fitnessconsultant/foradvice__________________________________________________4.illegal/dangerous/take/drugs__________________________________________________5.harmful/skipbreakfast/often_____________________________________________2Itisusefultoturntoafitnessconsulantforadvice.Itisdangeroustotakeillegaldrugs.Itisharmfultoskipbreakfast(too)often.Completetheconversationswiththecorrectformsofthephrasesinthebox.31.A:Hello,doctor.Iwanttoloseweight,butIjustcan’tseemtodoit.Whatcanyoudotohelpme?B:Well,first,it’snecessaryto______________whatyoueat.Cutoutallfattyfoodandsugarydrinks,andeatmorefruitandvegetables.2.A:Ireallyneedto_________awaytoexercisemore.Icoulduseafitnessapp,butmyphone’sfull.B:Sodeleteafewfiles.I'msuretheappdoesn’ttakeupmuchspace.beginwithbeincontrolofmakeachoicedecideonmakeupone’smindbeincontrolofdecideon3.A:Beforeexercising,alwaysdoafewwarm-upsto__________.B:Iknow.ButthenIalwaysfeeltootiredtocontinue!4.A:ShouldIgo